 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Air carrier captain reported losing both GPS signals; which he attributed to military activity in the area. He successfully switched to an alternative means of navigation until the GPS signal was restored.
| Attributes | |
| ACN | 1354554 |
| Time | |
| Date | 201605 |
| Local Time Of Day | 0601-1200 |
| Place | |
| Locale Reference | ZOA.ARTCC |
| State Reference | CA |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | Widebody Low Wing 2 Turbojet Eng |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Cruise |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | GPS & Other Satellite Navigation |
| Person 1 | |
| Function | Captain Pilot Flying |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types Inflight Event / Encounter Other / Unknown |
Narrative:
Initially noticed an EICAS ATC alert. Also heard another aircraft say they lost their GPS reception. 5 minutes later we lost both GPS signals. We followed the QRH procedure. On step 2 of that procedure it says to use radio (DME) updates 'if allowed'. Neither the QRH; nor the fom; nor any other publication available to the crew tells us whether we are 'allowed' to select and use radio updates. Since the inertial platform was drifting off course rapidly; we selected radio updates and our navigation accuracy returned to normal. We did not get the right GPS back online until east of stl; and we didn't get the left GPS signal back until east of cle. The crew needs more QRH information regarding this procedure.
Original NASA ASRS Text
Title: Air carrier Captain reported losing both GPS signals; which he attributed to military activity in the area. He successfully switched to an alternative means of navigation until the GPS signal was restored.
Narrative: Initially noticed an EICAS ATC alert. Also heard another aircraft say they lost their GPS reception. 5 minutes later we lost both GPS signals. We followed the QRH procedure. On step 2 of that procedure it says to use radio (DME) updates 'if allowed'. Neither the QRH; nor the FOM; nor any other publication available to the crew tells us whether we are 'allowed' to select and use radio updates. Since the inertial platform was drifting off course rapidly; we selected radio updates and our navigation accuracy returned to normal. We did not get the right GPS back online until east of STL; and we didn't get the left GPS signal back until east of CLE. The crew needs more QRH information regarding this procedure.
Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.